Production of embossed fibrous sheets

ABSTRACT

Composite fiber structures comprising a sheet of fibrous material having an open-patterned web of plastic material at least partially embedded in the fibers of the sheet are made by applying to at least one surface of a sheet of fibrous material, such as felted, knitted, woven or otherwise associated wool or other animal, vegetable or synthetic fiber, an open-patterned web of plastic material and subjecting the web successively to conditions effective to cause at least partial penetration of the fibrous sheet by the plastic material and to conditions effective to harden the plastic material, preferably with the concomitant application of pressure to the plastic material while it is in flowable condition. After hardening the plastic the assembly may be subjected to wetting out and drying to effect further expansion of the fibrous sheet between the elements of the plastic web. The fibrous material may be given a differential color from the plastic material by dyeing the fibrous material after the application of the web of plastic material or by applying to the fibrous sheet a web of differently colored plastic material.

Unite States ateiit 1191 Mizell et al.

[ Oct. 30, 1973 PRGDUCTION 0F EMBOSSED FHBROUS SHEETS [75] Inventors: Louis R. Mizell, Chelmsford, Mass;

Mary S. Schur, Manassas, Va.

[73] Assignee: 1. W. B. Nominee Company Limited,

London, England [22] Filed: Apr. 9, 1971 [21] Appl. No.: 132,815

abandoned.

[30] Foreign Application Priority Data July 19, 1967 Great Britain 33,123/67 [52] U.S. Cl 156/83, 117/37 R, 117/65.2,

[56] References Cited UNITED STATES PATENTS 2,543,101 2/1951 Francis l6l/l50 2,880,111 3/1959 Drelich et a1. 117/37 R 2,900,291 8/1959 O'Connell 161/148 3,047,444 7/1962 Harwood 161/128 3,313,270 4/1967 Labombarde et al 117/38 X 3,459,615 8/1969 Eilerman 156/306 X 3,474,952 10/1969 Cover et al.. 156/306 X 3,684,603 8/1972 lltis 156/209 X 3,695,984 10/1972 Rogers..... 161194 X 3,708,366 l/1973 Donnelly 156/209 3,720,571 3/1973. Caroselli et a1 161/128 X Primary Examiner-Harold Ansher Attorney-Stowell & Stowell [57] ABSTRACT Composite fiber structures comprising a sheet of fibrous material having an open-patterned web of plastic material at least partially embedded in the fibers of the sheet are made by applying to at least one surface 'of a sheet of fibrous material, such as felted, knitted, woven or otherwise associated wool or other animal,

vegetable or synthetic fiber, an open-pattemed web of plastic material and subjecting the web successively to conditions effective to cause at least partial penetration of the fibrous sheet by the plastic material and to conditions effective to harden the plastic material, preferably with the concomitant application of pressure to the plastic material while it is in flowable condition. After hardening the plastic the assembly may be subjected to wetting out and drying to effect further expansion of the fibrous sheet between the elements of the plastic web. The fibrous material may be given a differential color from the plastic material by dyeing the fibrous material after the application of the web of plastic material or by applying to the fibrous sheet a web of differently colored plastic material.

4 Claims, 5 Drawing Figures 1 PRODUCTION OF EMBOSSED FIBROUS SHEETS CROSS REFERENCE TO RELATED APPLICATION This application is a continuation of applicants parent application, Ser. No. 745,759, filed July 18, 1968, now abandoned.

This invention relates to novel sheet fiber structures having embossed patterns in one or both surfaces of the sheet consisting of open-patterned webs of plastic material embedded in one or both surfaces of a fibrous sheet whereby permanent decorative effects and/or reinforcement of the resulting sheet structures are attained.

The novel structures may be provided by applying to at least one surface of a sheet of fibrous material an open-patterned web ofa normally solid plastic material and subjecting the web successively to conditions effective to cause at least a partial penetration of the fibrous sheet by the plastic material and to conditions effective to harden the plastic material. Preferentially the assembly is subjected to pressure while the thermoplastic material is in the softened condition, either generally, or topically in the locus of the plastic web.

The fibrous sheet may be a batt or a felted, knitted or woven sheet of animal, vegetable or synthetic fiber or mixtures thereof. The method of the invention is particularly adapted to the embossing or reinforcing of sheets consisting of or containing wool or similar animal fibers or consisting of or containing synthetic fibers of relatively high softening point, such as the polyamide and polyester fibers.

The applied web may consist of any of the thermoplastic materials, such as polyethylene, polypropylene, poly (vinyl halides), poly (vinylidene halides) or mixtures or copolymers thereof. Th thermoplastic material may be applied to the fibrous sheet in the form of an open-patterned web wherein the pattern is preformed by perforating a solid sheet, by casting or by weaving, as in the form of monofil nets. The thermoplastic may also be applied to the fibrous sheet in the molten condition by impressing in pattern form from embossed or engraved rolls or by spraying or wiping the molten thermoplastic on the fibrous sheet through patterned stencils, or by spraying or extruding through patternpositioned nozzles.

Instead of applying thermoplastic material to the fiber sheet a solution of a plastic in a volatilizable solvent may be printed or sprayed in pattern form and the plastic thereafter hardened by volatilization of the solvent, or a heat-hardenable plastic composition, such as an uncured phenolic or aminoplast resin in flowable condition, may be applied to the sheet in pattern form and the applied position then subjected to curing conditions. preferably by the simultaneous action of heat and pressure.

It is, of course, desirable to select plastic materials which may be softened and/or hardened under conditions which will not adversely affect the fibers used.

By subjecting the structure to wetting out and drying after the plastic web has been hardened, the fibers in the openings of the plastic web tend to expand to form embossed three-dimensional patterns. This expansion is particularly pronounced with fibrous sheets consisting of or containing animal fibers such as wool. The expanded areas may be brushed or teased out into a pile.

The principles of the invention will be further illustrated in the following specific example described with reference to the accompanying drawings in which:

FIG. 1 is a surficial view of a portion of felted fabric; FIG. 2 is a transverse section on line 2 2 of FIG.

FIG. 3 is a surficial view ofa portion of extruded netting of thermoplastic material;

FIG. 4 is a surficial view of a portion of fiber structure embodying the principles of the invention; and

FIG. 5 is a transverse section on line 5 5 of FIG.

In a representative embodiment of the method aspect of the invention there was superimposed on a portion of all-wool hardened and fulled felt 10(FIGS. l and 2), weighing 22 oz/sq. yd., a portion of similar size of extruded polypropylene netting 12 (FIG. 3) having 1/4 X 1% inch openings 14 and weighing 3.9 oz/sq. yd. A piece of siliconized paper was placed on top of the netting and the assembly was placed in a hydraulic press having electrically heated platens.

A pressure of 200 lbs/sq. in. was applied to the assembly with the top platen (in contact with the release paper) heated to 350 F. and the bottom plate heated to 300 F. After 30 seconds, the hot-pressed assembly was removed from the press. The top surface was flat and relatively smooth and the pressed assembly was substantially thinner than the original felted sheet. The pressed assembly was then wetted out in water, squeeze roll extracted and dried. During the wetting the felt expanded between the lines of plastic to approximately the original thickness of the felt resulting in a final product with an embossed three-dimensional surface 16 as shown in FIGS. 4 and 5.

When the polypropylene netting is applied to a Dacron felt (formed by needle punching and heat shrinking) and subjected to the same conditions of hotpressing, wetting and drying, a similar product is formed except that the Dacron felt does not pop-up" as much between the embedded plastic strands.

The fiber structures produced by these procedures are useful in the production of uppers for womens shoes and slippers as well as for hats and other apparel; for purses and luggage; for attractive acoustical panels for walls and ceilings; and for many other uses.

Application of similar treatment to an assembly of polypropylene netting and a light weight, easily distorted knitted wool fabric weighing about 6 oz/sq. yd. results in a fabric of stabilized structure with an embossed surface.

With the heated platen in direct contact with the applied plastic web of the assembly the resulting fabric varies remarkably in appearance depending on the surface finish of the platen. When the platen has a dull matte surface the plastic web of the resulting fabric is inconspicuous, while if the platen has a smooth, highly polished, chrome-plated surface the plastic web is shiny and quite conspicuous.

Other pattern effects, useful not only in articles of apparel but also for table mats, table covers, pillow covers and the like, can be obtained by subjecting the plastic web-fiber sheet assemblies to lower temperatures and- /or pressures.

After applying plastic web to one or both surfaces of the fiber sheet, a further sheet of the same or a different fiber may be superposed on the plastic web before subjecting the assembly to the treatment of the invention.

In this way fiber structures having a web or webs or reinforcing plastic in the interior of the structures are obrained.

Soft, lofty, inexpensive textile fiber batts, such as carded-only batts, needle-punched batts and hardenedonly batts can be given a quilted effect and strengthened for dyeing and for functional uses by the process of the invention. For example, a lightly needled wool batt (needle-punched 400 penetrations per square inch of batt), embedded with a clear polypropylene netting with large cut-out designs were hot pressed at 100 lbs/sq. in. with the platen in contact with the netting heated to 350 F. Finishing effected by treatment with live steam for a few minutes resulted in stabilized decorative fiber structures useful for air filters; wall and ceiling coverings; bed and stadium blankets; coats and jackets and other winter wear.

By subjecting pile fabrics to the method of the invention followed by brushing up the pile in the areas between the plastic, sculptured pile fabrics useful for rugs, bath mats and novelty articles are obtained.

By varying the amount of pressure applied during the process of wide variation in the amount of compression of the fiber sheet in the locus of the applied plastic can be obtained. When working with a wool felt approximately 0.09 inch in thickness (22 oz/sq. yd.) with a platen temperature in contact with the thermoplastic about 425 F the pressure may be between about 25 and about 500 lbs/sq. in. and the dwell time in roll presses may be from fraction of a second to about 15 seconds and in platen presses from about 10 seconds to about 2 minutes. These parameters are interrelated and, in general, as one is increased another can be decreased. The minimum temperatures must be high enough to cause the applied plastic to flow at the pressure and time of treatment but below the temperature of plastic flow of the fiber and not high enough to cause excessive flow of the plastic at the pressure and time of treatment.

We claim:

1. A method of producing a permanently embossed fibrous sheet which comprises applying a pattern of normally solid thermoplastic material to a sheet comprising proteinaceous fibers, subjecting the sheet carrying the pattern of applied thermoplastic material simultaneously to a temperature above the softening point of the thermoplastic material and to pressure effective to reduce the thickness of the sheet by at least 25 percent whereby the thermoplastic material penetrates and is bonded to the sheet and the sheet is temporarily set in the compressed state, and thereafter releasing the pressure and subjecting the composite sheet to the action of moisture whereby the fibrous sheet selectively innetting of 350 F. and maintaining pressure for sec- I onds, variations in percentage reduction in felt thickness of from about 25 percent to about 55 percent can be obtained by varying the pressure in the range from 25 to 500 lbs/sq. in. After wetting out'and drying the permanently embossed patterns in the felt have depths in the range of about 30 percent to 40 percent, the depths increasing with increase of pressure during the hot pressing operation.

For continuous processing, the assembly of fiber sheet and thermoplastic web, with or without an outer parting sheet, may be passed between press rolls maintained at the desired temperature, pressure and speed of rotation.

In general, depending on the characters'of the fiber sheet and the plastic web and on the desired characteristics of the resulting product, the temperature of the hot rolls or platens may be between about 250 F. and

' wool.

creases in thickness in the areas'not containing the thermoplastic material.

2. A method of producing an embossed fibrous sheet as defined in claim 1 wherein the fibrous material is vent therefrom.

- l: i I1 

2. A method of producing an embossed fibrous sheet as defined in claim 1 wherein the fibrous material is wool.
 3. A method of producing an embossed fibrous sheet as defined in claim 1 wherein the pattern of thermoplastic material is applied to the sheet comprising proteinaceous fibers by impressing the plastic on the sheet in flowable condition from relief-patterned rolls.
 4. A method of producing an embossed fibrous sheet as defined in claim 1 wherein the pattern of thermoplastic material is applied to the sheet comprising proteinaceous fibers by impressing a flowable solution of the plastic in a volatilizable solvent on the sheet from relief-patterned rolls and thereafter volatilizing the solvent therefrom. 